Aquinas: reason and telos

Aquinas holds that everything has a God-given telos (purpose), and the human telos is to flourish and be united with God. He sets out four tiers of law:

• Eternal law — God wisdom governing all things.
• Divine law — revealed law (scripture).
• Natural law — the moral law knowable by human reason.
• Human law — the laws societies make.

The first principle, synderesis, is 'do good and avoid evil'. From this, reason works out how to live.

The five primary precepts

Reason identifies five primary precepts — universal goods that fit the human telos:

• Preservation of life.
• Reproduction (continuation of the species).
• Education of the young.
• Worship of God.
• Ordered society (living peacefully in community).

These are absolute and universal — the same for everyone, everywhere.

A primary precept

Secondary precepts and real goods

Secondary precepts are the more specific rules that reason derives from the primary precepts. From 'preserve life', for example, reason derives 'do not murder' or 'defend the vulnerable'.

• Because they are reasoned out, secondary precepts can be applied to particular situations.
• Aquinas distinguishes a real good (which genuinely fits our telos) from an apparent good (which only seems good — e.g. an adulterer pursues pleasure they mistake for a real good).

Where do secondary precepts come from?

Primary or secondary?

Tap a precept, then whether it is primary or secondary.

Acts and the doctrine of double effect

Aquinas says both the interior act (intention) and the exterior act (the deed) matter — a good act done from a bad motive is still wrong.

The doctrine of double effect allows an act with two effects — one good and intended, one bad but only foreseen, not intended — provided:

• the act itself is good or neutral;
• the good effect is intended and the bad merely tolerated;
• the good outweighs the bad.

Classic case: giving a dying patient pain relief that also shortens life — the intention is to relieve pain, not to kill.

Double effect

Strengths, criticisms and developments

Strengths: clear, universal, rational, and available to all people (not just believers).

Criticisms:

• Karl Barth: it puts too much confidence in human reason and too little in revelation and grace.
• It can be too rigid / legalistic, ignoring the situation and consequences.
• It may commit the naturalistic fallacy — moving from how nature is to how we ought to act.

Development — proportionalism (Bernard Hoose): one may set aside a precept if there is a proportionate reason, softening the absolutism.

Key terms

Tap a term, then its meaning.

A criticism

The big ideas to take into the exam

Natural Law is the absolutist benchmark for the theories that follow. Press Finish.