Kant: Preface, Section 1 & 2

Kant speaks of Hume in a positive way, but questions Hume on the origin of cause and effect knowledge. Hume believed all cause and effect are a posteriori. However, Kant takes the opposing position, that cause and effect is a priori. Not only is cause and effect a priori but also metaphysical concepts. “…Metaphysical cognition, its very concept implies that they cannot be empirical. Its principles must never be derived from experience…It is therefore a priori cognition, coming from pure understanding and pure reason.” (Section 1, p. 9)
Kant thoroughly explained his belief concerning analytic and synthetic judgments. Unlike other philosophers, Kant believed that synthetic judgments could either be a posteriori (judgments from experience) or a priori (mathematical judgments). However, analytic judgments are always a priori and apply the principle of contradiction. For example, I can say females are women and to say females are men would be contradictory. Kant uses the example, “all bodies are extended.” To say all bodies not are extended would be contradictory. However, “all bodies have weight” would be a synthetic judgment. To say all bodies do not have weight is not necessarily contradictory, although, it may be false. For instance, I could say females are good at English. To say they are not is not contradictory since these judgments come from experience. Kant also argues that mathematical judgments are synthetic but a priori. Using as an example 7 + 5 = 12, Kant states, “The concept of twelve is by no means thought by merely thinking of the combination of seven and five…we must go beyond these concepts by calling to our aid some intuition corresponding to one of them.” (Section 2, p. 11) Not only is arithmetic a priori synthetic but so is geometry. For example, the proposition that a straight line is the shortest way to go between two points requires intuition. The concept of a straight line gives no intimation of quantity, only quality.