issues with moral realism

moral realism

the theory that claims that moral properties exist and exist mind-independently

hume’s fork

hume argues that knowledge can be of two kinds; matters of fact and relations of ideas

moral realism

the theory that claims that moral properties exist and exist mind-independently

hume’s fork

hume argues that knowledge can be of two kinds; matters of fact and relations of ideas

matters of fact

matters of fact are propositions that are understood a posterori and discovered through experience

about what exists and what is the case

such propositions are synthetic truths, meaning they are true on the virtue of the how the world is

e.g. Paris is the capital of France

relations of ideas

relations of ideas are propositions that are understood a priori and can be discovered purely through deduction

they are analytically true, meaning their truth depends on the meanings of the concepts involved and are ‘either intuitively or demonstratively certain’ such as all triangles have three sides

they cannot be denied without contradiction

hume’s fork against realism

hume claims there can be only two kinds of knowledge; matters of fact and relations of ideas

moral judgements are not judgements of reason and we cannot have knowledge of them because they do not fall into either category

mind-to-world direction of fit

when you change your beliefs to fit the world

world-to-mind direction of fit

when the world changes to fulfil our desires

hume’s argument from motivation (standard form)

p1. moral judgements can motivate our action

p2. reason cannot motivate our actions

c. therefore, moral judgements are not judgements of reason

hume’s motivation argument

cognitivism claims that moral judgements express beliefs which can be true or false and the faculty of judging what is true or false is reason

hume’s ought-is gap

cognitivist would say ‘eating meat causes animal suffering, therefore we shouldn’t eat meat’ according to the cognitivist the truth of this claim is inferred from the premise

hume argues that cannot infer one from the other because the premise tells me how the world is and the conclusion tells me how the world ought to be - there is a gap between the two, so we cannot reason one from the other

if moral judgements were true we would be able to infer them from other true claims, but we cannot

therefore moral judgements don’t make truth claims and cognitivism is false