Speculative reason or
pure reason is theoretical (or
logical,
deductive) thought (sometimes called theoretical reason), as opposed to practical (active, willing) thought. The distinction between the two goes at least as far back as the
ancient Greek philosophers, such as
Plato and
Aristotle, who distinguished between
theory (
theoria, or a wide,
bird's eye view of a topic, or clear vision of its structure) and practice (
praxis), as well as
techne.