Much of our thought has to deal with hypotheses, namely, to go beyond the statement of isolated facts and direct forms of qualitative inference. Indeed, much of humans' inferential activity in daily life, professional settings, and scientific investigation relies on hypothetical premises, or concerns hypothetical conclusions. 

One aspect of reasoning with hypotheses is using conditionals, namely, if-then statements of how a consequent depends on a contingent antecedent clause. 

A second aspect is dealing with uncertainty, namely, reasoning about a state of affairs that may or may not obtain on the basis of given evidence. In both cases, the target of reasoning may well have to do with other agents, as it happens in strategic games, communication or negotiation.

Reasoning with hypotheses plays a key role in both learning about the environment and social interaction.