Natural law theories propose that there are objective, universal principles of morality that can be discovered by reason and that inform just positive law. Key thinkers in the natural law tradition include Aristotle, Aquinas, Hobbes, Locke, Fuller, Finnis, and Hart. They variously argue that natural law is derived from human nature, God, or basic human goods. For Aquinas, natural law comes from eternal law and practical reason, and just human laws should conform to natural law. Finnis develops a secular natural law based on seven basic human goods. Critics argue natural law is not objective or universal and simply imposes personal views under the guise of rational principles.

1. NATURAL LAW
• Based on unchanging guiding principles to which human laws are expected to conform
• Laws and morals intersect: creates law to conform to notions of good, morality or ethics
Natural law themes
• What is law’s relationship to individuals and communities?
o Law does not exist in isolation, it relates/connects to society and its needs
• Where is the limit between the desire for a personally beneficial law and the way this law will
affect others?
o Needs of society prevails (but see Fuller)
• What if the law is a bad law?
o Finnis: wrong to disobey such a law, if disobedience would adversely affect community;
up to the ruler to change the law
o Fuller: concepts of ‘right’ or ‘good’ should prevail, such a law should not be obeyed; all
people have natural rights that cannot be taken away
• What is the role of the legislature and the courts?
o Human law
o When natural law guides human law, human law will be ‘good’ law
Subject matter of natural law
• Aristotle, Cicero, Aquinas, Finnis: natural law lead to good human law, so individuals,
community or state will flourish
• Support and maintain basic legal principles: explains the need for protection of persons,
property and promises (Hobbes, Locke, Hart and Finnis)
• Natural rights protect fundamental human rights
• Natural law is a system or structure which enables us to derive forms of law based in
observation about human nature.
Aristotle – ‘The Politics” and “The Ethics”
• Reason and wisdom
• Best govt: a balance between tyranny and democracy
• Teleology: a system of reasoning; what is the perfect form to aspire to (perfect: completed all
goals, reached full form)
o Living in a society is a natural good that all persons will thrive for
o Law enhances this society by supporting the virtuous life
o Natural law: universal; Legal or conventional law: apply as needed to an individual
society for its own needs. E.g. justification for equity – a conventional law
Cicero – “De Re Publica” and “De Legibus”
• Cicero was a stoic: aspire to live a virtuous life, obtained through courage, justice and right
living.
o Created an ethical framework to guide behaviour, framework relied on REASON, the
NATURAL ORDER of things and the COSMIC ORDER of the world
o Reason automatically leads a person to understand the naturally appropriate behaviour to
reach virtue
• True law = right reason + nature (therefore, no tyranny)
• True law = universal, eternal and unchangeable (as natural law came from the cosmic order)
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2. Aquinas – linking God with human law
• Aquinas created a new type of theology, connecting it with Aristotelian reason, order, virtue and
community
What is law?
• Law is a binding set of obligations on people to achieve virtue, which is directed by reason.
Thus, will of a ruler can become law so long as it is based on reason
• Purpose of law is the wellbeing of society
• Used Aristotle’s teleology to explain that individual good is inferior to the common good
• Law = rational ordering of things concerning the common good; The maker of law – the ruler –
uses practical reason to rule the perfect community
What are the various types of law?
• Q91
• Eternal law: source of guidance given by God, God governs by divine reason
o Humans can selectively participate in aspects of eternal law using their reason
o Natural law therefore comes from human reason
o Natural law can be used to create human law, which will fill out and detail natural law
for day-to-day purposes
What are the characteristics of natural law?
• Q94
• Instructions of natural law equate to our natural inclinations. E.g. we have natural inclinations to
good, to preserve human life, to produce children etc
• Using reason to guide behaviour: speculative reason (finds indisputable truths) and practical
reason (no clear outcome can be found; e.g. usually proper to repay debts, but it may be wrong
to do so in certain cases)
Diagram: Aquinas’ Structure
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3. How does human law connect to natural law?
• Q95
• Human laws are subordinate to natural law
• Some need more guidance to achieve a virtuous life than others; these people can only be
compelled to behave well through human law (penalty)
• Reason can be good, but it may be used to exploit base desires and cruelty – linking human law
to natural law
• Natural law is used as a set of general first principles under which human law is made using
reason
• Using natural reason leads to creation of good human law to deal with the needs of practical
situations not expressly covered by natural law: e.g. like specific rules of contract
• What if a human law completely contravenes a natural law – corruption of law. Thus, the
catholic church used this premise to ban contraception – this is derived from natural law to
continue all life.
o Aquinas more concerned with maintaining good community order than permitting a
person to disobey the ruler’s law
Hobbes – social contract and strong govt
• Social contract: people should give up individual liberty where there is a conflict with the needs
of strong government (a monarch), in return for protection
• Natural state of human is ‘solitary, poor, nasty, brutish and short’; no law, no concept of right or
wrong
• The Sovereignty is not one person, but a group of individuals (commonwealth)
Locke – property, and rights against government
• Individual liberty
• Everyone’s free and equal, with property rights and limited government intervention
• Separation of powers
• Role of govt: preservation of property
Inalienable Rights:
• Social contract: allow men to enjoy their inalienable rights, given by God – right to life, liberty,
property
• Nature was given to us by God, but it did not provide property protection. Only when we mix
our labour with nature and transform property then we can claim land
• Labour = work of labours, animals and anything over which the land owner possess control
Exercise of Inalienable Rights:
• Power to preserve property (life, liberty and estate) – in civil society, this occurs by law and is
exercised by men in authority to carry out punishment; BUT without such law, a person can
exercise this right for himself
Creating Human Law:
• Links with Aquinas – will of God
The Gap – from the Age of Reason (rise of positivism) to WWII
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4. • Mistrust of the methods used by natural law theorists and their reliance on what could not be
proved; emphasis on scientific method
• During WWII, Nazi genocide prompted a rethink of positivist method and a revival of natural
law
Fuller – connecting morality with law
• Argued that Nazi Germany did not have the internal morality needed for a legal system to be
valid - Moral issues SHOULD BE considered by the courts
• C.f. Hart – moral issues should NOT be considered in a legal system, law cannot be invalidated
on the basis of morals, only a retrospective law can be enacted to amend the bad law
Reviving Aristotle’s community and common good
• Created a secular, human, anti-metaphysical natural law, using legal rules and procedures to
support his argument
• A ruined legal system means no legal system at all and leads to a ruined society – 8 ways to ruin
a legal system:
1. There are no rules at all – this means cases are decided ad hoc
2. Rules aren’t made available to people affected by law
3. Retrospective legislation is used in an abusive sense, leaving people unsure about what
will happen to any law
4. Rules can’t be understood
5. Rules are contradictory
6. Rules that require you to do something that is impossible
7. Laws that change so often that you can’t work out your actions
8. A gap between publicise laws and their administration
• If the bond between govt and citizen breaks down, citizens do not have to obey laws
• Whereas these ways will lead to perfection:
1. Clear rules
2. consistent rules
3. every citizen knows them
4. rules are never retrospective
5. rules can be understood
6. rules remain constant
7. rules only demand what is possible
8. rules are observed by courts, police and administration
Inner Morality of Law – how to make a legal system work for the good of the community
• the inner morality of law (procedural natural law) is a lower law, c.f. to natural law, it is like
what a carpenter would use to make sure a building would hold up
• concerned with how the system of rules governing human conduct should be constructed and
administered
• a balancing act: diagram
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5. Hart’s minimum content of natural law
• certain rules of conduct are required to maintain a society are ‘pre-legal’ – precede the existence
of law and a legal system; need these rules as a minimum for survival, to enable us to live
together and be able to continue our existence with each other
• 5 facts of human condition
• Rules are need for protection of persons, property and promises and to impose sanctions
• Revival of Hobbes’ and Locke’s social contract
• Legal system survives because people accept the rules as they are fair
Reviving Aquinas – John Finnis
• No connection with God, observations about nature or morality in the sense of goodness
• Natural law is derived on the basis of a set of self-evident basic goods on which human
existence is based
Reviving Aristotle and Aquinas – individuals, community and law
• Natural law is the set of principles of practical reasonableness in ordering human life and human
community
o Aims to provide guidance to living a good life which leads to a good and harmonious
society
o Role of law: preserve common good
Finnis’ Structure
• Multi-layered method:
• 7 innate basic human goods: self evident; everyone strives for them; exist before morals; exist
irrespective of culture.
o LIFE: living and living well, procreation (Finnis is against abortion and artificial
reproduction)
o KNOWLEDGE
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6. o PRATICAL REASONABLENESS: use of reasons in actions, habits and practical
attitudes
o PLAY
o AESTHTIC EXPERIENCE
o SOCIABILITY OR FRIENDSHIP
o RELIGION
• The first moral principle: assists human decision making, decide between right and wrong
o In voluntarily acting for human goods, and in avoiding what is opposed to them, one
ought to choose (and otherwise will) those and only those possibilities whose will is
compatible with integral human fulfilment
• Adding in the 9 basic requirements of practical reasonableness:
o Provides a set of moral and ethical criteria attached to the actions that guide the
goods
o Combined with goods, they make up natural law
The role of law, natural law and human law
• Deriving human law from natural law
• 1st
order principles (or practical reasonableness) are guided by 2nd
order principles, a legislator
that ignores 1st
order principles will have their law challenged and overturned by 2nd
order
principles
• Using practical reasonableness:
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7. Obeying the law – denying lex injusta non est lex
• Must obey an unjust law, for the common good
• Only the ruler can change a corrupt law – ruler can find out about an unjust law through
practical reasoning; Ruler is responsible to repeal the unjust law, not enforcing it
Critical responses to Finnis
• He had discarded all the underlying principles of natural law
• He is simply imposing his world view on all of us through the guise of practical reason
• He is embedding Catholicism in the guise of universality (supports a particular set of moral
principles and denies others)
Critical response to natural law theories
• Natural law’s claim of to be universal and immutable: human conduct is clearly driven by
context, politics, and historical circumstance
• Natural law is simply an argument for personal, conservative views. It supports unfair laws and
is based on political structures designed to prop up inequalities – Finnis
• The theory simply doesn’t work!
• Theory is irrational, and questions of law never need to be concerned with morals (modernism
and positivism).
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