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Virtue in Machine Ethics: An Approach Based on Evolutionary Computation

Virtue in Machine Ethics: An Approach Based on Evolutionary Computation

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February 2015. Co-author: Don Howard, University of Notre Dame). Presented at the American Philosophical Association (APA Central). St. Louis, Missouri.

February 2015. Co-author: Don Howard, University of Notre Dame). Presented at the American Philosophical Association (APA Central). St. Louis, Missouri.

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Virtue in Machine Ethics: An Approach Based on Evolutionary Computation

  1. 1. Virtue in Machine Ethics: An Approach Based on “soft computing” Ioan Muntean imuntean@nd.edu University of Notre Dame and UNC, Asheville Don Howard University of Notre Dame dhoward1@nd.edu
  2. 2. Mapping the “Machine Ethics” (aka “Computational Ethics”) • Machine ethics: ethics of actions and decisions of machines, when they interact autonomously, mainly with humans (but also with other machines, with animals, with groups of humans, corporations, military units, etc.) (Allen and Wallach 2009; Anderson and Anderson 2011; Abney, Lin, and Bekey 2011; Wallach 2014) • Compare and contrast with “Ethics of Technology”: the ethical impact technology or science have. Here, the ethical decision or responsibility belong to humans.
  3. 3. Machine ethics at large Major differences from ethics of technology: • the human-machine ethics is not fully symmetrical, but more balanced: • technology is not purely passive, • machines are agents and • machines have moral competency and share it with humans. • New social relationship with machines: humans train and select machines. • A new type of relation of human-machine “trust” • Moral advising from AMA? • If successful, the machine ethics approach would make us accept robots as similar to humans, keeping in mind that exceptions do occur: in some unfortunate cases the moral AMA can misbehave badly • Applied ethics question: is there an analogy between AMA and domesticated animals?
  4. 4. The “other” moral agents? • We are moral agents • Are there other moral agents? • animals • companies • the government • angels • philosophical zombies • groups of people • young children (at what age?) • Artificial moral agents are not humans, albeit they are individuals • If they are autonomous, we call them AMA. • Some non-human moral agents are not individuals.
  5. 5. What is an autonomous moral agent (AMA)? AMA makes moral decisions (by definition), and discerns right from wrong What is not an AMA? • ATS system used in trains • Driverless cars are not AMA, but may include an AMA module AMA operations: • sampling the environment • separating moral decisions from non-moral decisions • adapting to new data • Using its own experience and (socially) the experience of other AMAs Features of AMA: • Complexity • Degrees of autonomy • Creativity and moral competency
  6. 6. The “no-go” argument • Many argue for negative answers to these questions or limit drastically the concept of AMA (Johnson 2011, Torrance 2005) • The dominant stance towards an AMA is a form of a “folk (artificial) morality” argument • Human agents have one or more of these attributes: personhood, consciousness, free will, intentionality, etc. that machines cannot have. • Moral decisions are not computable • Therefore, computational ethics is fundamentally impossible
  7. 7. Foundational questions for many AMA projects • Q-1: Is there a way to replicate moral judgments and the mechanism of normative reasoning in an AMA? • Q-2: What are moral justifications and normative explanations in the case of AMA? • Q-3: Is there a way to replicate in an AMA the moral behavior of human moral agents? • Our project is more about Q-3, than about Q-1 and Q-2. • The no-go stance reject positive answers to Q1-Q3.
  8. 8. Moral functionalism against the “no-go” stance • Assume a form of naturalism in ethics • Argue for moral functionalism (Danielson, 1992). • Argue against moral materialism: AMAs do not need to be human- like or even “organic”. • Other questions: Do AMAs need to evolve, self-replicate or create? Do they learn from humans or from other AMAs? • The category of entities that can be moral agents is determined by their functional capabilities, not by their material composition or even organization. • Computational systems can be moral agents. • If moral functionalism is right, we can advance to the thesis that computational ethics is in principle possible.
  9. 9. Philosophical approaches to AMA • Metaphysical AMA: central role for philosophical concepts about morality. The most likely concepts involved are: free will, personhood, consciousness, mind, intentionality, mental content, beliefs. This approach is premised on some philosophical doctrines about these concepts. • Ethical AMA: adopt first an existing ethical model (deontological, consequentialism, Divine command theory, etc.) without assuming too much about the nature or the metaphysics of the human moral agent or about the moral cognition; then adopt a computational tool in order to implement it. See the “top-down” approach (Allen and Wallach 2009) • Cognitivist AMA: the essential role of the human moral cognition in AMA. It needs an empirical or scientific understanding of the human cognitive architecture to build an AMA (and not of abstract ethical theories). • Synthetic AMA: the implementation of AMA is not premised on any knowledge about human moral agency or any ethical theory. Moral skills and standards are synthetized from actions and their results by a process of learning. See “bottom-up” models (Allen et al. 2005). And last but not least:
  10. 10. Constructivism AMA • An ethical framework is used only partially, as a scaffolding to build AMA. This moral framework, more or less suitable to describe humans is reshaped and reformulated to fit the artificial moral agent. This approach is probably close to the hybrid approach discussed in Allen
  11. 11. Cognitivist AMA vignettes • “machine ethicists hoping to build artificial moral agents would be well-served by heeding the data being generated by cognitive scientists and experimental philosophers on the nature of human moral judgments.” (Bello and Bringsjord 2013, p. 252). • The “point-and-shoot” model of moral decision making (J. D. Greene 2014)
  12. 12. Cognitivism and moral functionalism • We do not assume that only individual human minds can make moral decisions. It is just that up to now we have not had enough reasons to assume that animals, machines, or other forms of life are not moral agents. • We assume here a form of multiple realizability of moral decision making. Several realizations of moral agents are possible: highly- evolved animals, artificial moral agents built upon different types of hardware (current computer architecture, quantum computers, biology-based computational devices #, etc.), groups of human minds working together, computers and humans working together in a synergy. • Hence we reject individualism and internalism about moral decisions. Group moral decisions and assisted moral decisions are potantially also options.
  13. 13. Constructivist AMA • We use virtue ethics, based on dispositionalism • We use particularism (Dancy 2006) (Gleeson 2007) (Nussbaum 1986) • We build an action-centric model • Our strategy is to plunder virtue ethics and used those feature which are useful • The best ethical approach to AMA may or may not fit the best ethical approach to humans: hence, virtue ethics of AMA is just a partial model of virtue ethics for humans: only some concepts and assumptions of a given virtue ethics theory are reframed and used here.
  14. 14. A first hypothesis • H1: COMPUTATIONAL ETHICS: Our moral (decision making) behavior can be either simulated, implemented, or extended by some computational techniques. The current AMA implements functionally the human moral decision making, and extends it. The question now is: What computational model is suitable to implement AMA? Provisional answer: not the standard hard-computing computation, but the soft computation.
  15. 15. Three more hypotheses of our AMA • H2: AGENT-CENTRIC ETHICS: The agent-centric approach to the ethics of AMAs is suitable and even desirable, when compared to the existing models focused on the moral action (action-centric models). • H3: CASE-BASED ETHICS: The case-based approach to ethics is preferable to principle-based approaches to the ethics of AMAs (moral particularism). • H4: “SOFT COMPUTATIONAL” ETHICS: “Soft computation” is suitable, or even desirable, in implementing the AMAs, when compared to “hard computation”. The present model is based on neural networks optimized with evolutionary computation.
  16. 16. Other AMA models • H2’: ACTION-CENTRIC AMA: the ethical models of AMA should focus on the morality of action, not on the morality of the agent • H3’: PRINCIPLE-BASED AMA: the ethical model of AMA should focus on moral principles or rules, not on moral cases (ethical generalism). The majority of other AMA models are based on H2’ and H3’
  17. 17. Agent-centric and case-based AMA • This is closer to a dispositionalist view about ethics • Our AMA is premised on moral functionalism and moral behaviorism, rather than deontology and consequentialism • We can train AMAs in moral decision the same way we train humans to recognize patterns or any regularities in data • Is moral learning special? • For moral functionalism, morality is all about the behavior of a well trained agent. • AMA can be trained and taught behavior
  18. 18. AMA and its Robo-virtues • Suggestions from the machine ethics literature: • “the right way of developing an ethical robot is to confront it with a stream of different situations and train it as to the right actions to take” (Gips 1995). • “information is unclear, incomplete, confusing, and even false, where the possible results of an action cannot be predicted with any significant degree of certainty, and where conflicting values […] inform decision-making process” (Wallach et al. 2010, p. 457). • See also (Abney et al. 2011; Allen and Wallach 2009; Coleman 2001; DeMoss 1998; Moor 2006; Tonkens, 2012)
  19. 19. Virtue ethics and dispositionalism • Character traits “are relatively long-term stable disposition[s] to act in distinctive ways' (Harman 1999, p. 317). • Doris’s formulation of “virtue”: “if a person possesses a virtue, she will exhibit virtue-relevant behavior in a given virtue-relevant eliciting condition with some markedly above chance probability p” (1998, p. 509). • “Such and such being would have reacted to set {X} of facts in such and such way if the set of conditions {C} are met.”
  20. 20. A long-term aim of our AMA project • Like epistemology, ethics is one of the most dynamic areas of philosophy. Conjectures: • a significant progress in developing and programming artificial moral agents will ultimately shed light on our own moral ability and competency. Understanding the “other”, the “different” moral agent, questioning its possibility, is another way of reflecting upon ourselves. • Arguing for or against the “non-human, non-individual” moral agent does expand the knowledge about the intricacies of our own ethics.
  21. 21. Some computational concepts, some results
  22. 22. Knuth, 1973 “It has often been said that a person doesn’t really understand something until he teaches it to someone else. Actually a person doesn’t really understand something until he can teach it to a computer, express it as an algorithm [...] The attempt to formalize things as algorithms leads to a much deeper understanding than if we simply try to understand things in the traditional way.”
  23. 23. Soft computation • Hybridization between fuzzy logic, neural networks and evolutionary computation. • We use NN as models of moral behavior and evolutionary computation as a method of optimization • this talk focuses on the NN part • But there are partial results of the EC+NN available
  24. 24. What is a moral qualification? A function M from the quadruplet of variables <facts, actions, consequences, intentions > to the set of moral qualifiers Θ : , , ,M X A    
  25. 25. A moral decision model • x=physical (non-moral) facts • A=possible actions • Ω= physical consequences • =intentions of the human agent
  26. 26. The simplified lifeboat example • This example is inspired from the “lifeboat metaphor” • It involves a human agent, the person who is making the decision about the action. Here, the lifeboat has a limited capacity (let us say, under 4 seats). We assume that the human moral agent making the decision needs to be on the lifeboat (let us suppose she is the only one able to operate the boat or navigate it to a safe ground). The capacity of the boat is therefore between zero and four. In this simplified version, x has a dimension of 10 variables. (some are numerical variables which are • A number of persons are already onboard, and a number of persons are swimming in the water, asking to be admitted on the lifeboat.
  27. 27. Variables: X=physical facts • This vector encodes as much as we need to know about the physical constraints of the problem. For example, the trolley problem is a physically constrained moral dilemma . Here, in the simplified lifeboat metaphor, x is a collection of numbers of passengers onboard, persons to be saved from the water, the boat capacity , etc. At future implementations, one can add a vector for the passengers coding their gender, age, physical capacities, etc.
  28. 28. A=possible actions • Unlike the x this vector codes possible action taken by the human agent. In this simplified version, we code only the number of persons admitted onboard from the people drowning in the ocean. A negative value means that the human agent decided to force overboard a number of people from the lifeboat. • The action a can be: • 1 accept m persons from the water onboard action = +m • 2 accept nobody from the water, action =0 • 3 force n persons from the boat into the water, action =-n • Choosing an example that has “hidden moral aspects” and it is not a mere optimization of the output is part of this challenge. First, the present attempt is based on a simplified version of the lifeboat metaphor which does display a couple of moral behavior. Second, we attempt to reduce as much as possible using rules and a priori knowledge about moral reasoning.
  29. 29. Ω=physical consequences • This vector, codifies the non-moral consequences of the pair <x,A>, independent of intentions , and gives us an idea of what can happen if the human agent decides to take action a1, given the facts x1. • The consequences are here codified exclusively by the column physical_consequences • The reason to use the column is to code the constraints as relation among input data and NOT as a rule. Many law-based system can code the constraints as functionals (equalities or inequalities) among the input vector. Here, we decided to train the network in differentiating cases which are not possible from cases which are possible but are morally neural. By convention, all physically impossible cases are morally neural. • This is a debatable claim, but simplifies the coding procedure as well as the number of possible cases.
  30. 30. =intentions of the human agent • The column called “intention” is probably the most intriguing part of this implementation. The AMA is supposed to have some knowledge about the intention of the human boat driver. The most natural is to assume that she wants to save as many passengers as possible, which is in line with the consequentialist approach. But the driver can also be bribed by somebody in the water or in the boat, and her intention is to gain money. This case does imply some moral judgments.
  31. 31. NN as pattern recognition • They are able to recognize patterns in the moral data • They generalize from simple cases (here, the boat capacity) to more complex cases. • (See the excel files)
  32. 32. Some provisional observations • The best networks are able to discover moral anomalies (inconsistencies) in the train set. • They are inductive machines, but they are able to generalize to more and more complex cases. • Rules are emergent from the answer to the train set and not predefined • See case 14 and 14’ in the set. All best networks erred in predicting case 14. • We changed the case 14 to wrong. • Promising conjecture! • “The best networks discover inconsistencies in the test data” • They can flag out to trainers inconsistencies and errors. • The train set is not usually recategorized.
  33. 33. Robo-virtues before and after the EC • Provisional definition of robo-virtues • A population of neural network being able to consistently make a common decision on a set of data. • Presumably the application of EC will reduce the population of networks to one network that will display as an individual network such a robo-virtue.

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