What Came First: The Chicken or the Egg? David Hume moves through a logical progression of the ideas behind cause and effect. He critically analyzes the reasons behind those generally accepted ideas. Though the relation of cause and effect seems to be completely logical and based on common sense, he discusses our impressions and ideas and why they are believed. Hume's progression starts with his initial definition of cause, and moves on to his final conclusion in his doctrine on causality. As a result, it proves how Hume's argument on causality follows the same path as his epistemology, with the two ideas complimenting each other so that it is rationally impossible to accept the epistemology and not accept his argument on causality. .
Hume starts by explaining definitions of causes and characteristics that make up the popular definition of cause. Contiguity is the idea that things go together, or are results of each other. Whatever objects operate together as causes and effects are seen as contiguous. There are chains of causes that lead to every effect, whether or not they can be discovered they are presumed to exist. As Hume puts it, "Heat and light are collateral effects of fire, and the one effect may justly be inferred from the other" (160). Along with contiguity is the concept of succession. The cause must precede the effect. An object can be contiguous and occur prior to another without being its cause; a necessary connection between the two must be established. .
The relation of cause to effect does not depend on the known qualities of objects, but instead on the ideas of contiguity and succession, which are imperfect. Hume refutes the definition of cause as something productive of another, because cause and production are synonymous, and therefore one definition using the other is circular. Hume questions why it is necessary that everything, whose existence has a beginning, should also have a cause.
