For Leibniz, the truth of an analytic statement depends on its meaning, but for Hume, the truth of a synthetic statement does not depend on any external conditions or circumstances.
Hume built on the works of Leibniz and distinguished between analytic statements involving relations of ideas and synthetic statements of fact. Analytic propositions deal with the meaning of words and symbols, whereas synthetic propositions deal with reality itself. When we say that someone is tall, for example, we are using the word “tall” in an analytic sense. We are saying something about what it means to be tall, not literally describing someone’s height. Synthetic propositions, however, describe facts about the real world and are necessarily true. Hume argued that there could never be any evidence for synthetic propositions because we cannot go directly from concepts to objects, there are two different directions after a fork in the road. In his notion – only analytic propositions can be proven to be true, not synthetic ones – the fork cannot be crossed.
