Philosophy during the 'High Middle Ages' (1050-1300) was concerned with the matters of basic significance to human existence: the nature of being human, the purpose of human life, the existence and attributes of God, and morality. One important philosphical issue of the time concerned the relative roles of faith and reason. There were three basic viewpoints:
Viewpoint 1: Reason was irrelevant as it did not lead to salvation.
Plato and Socrates may oft contend,
And all the breath within their bodies spend,
Engaged in disuputations without end.
What's that to me?
For only with a pure and simple mind
Can one the narrow path to heaven find,
And greet the King; while lingers far behind,
Philosophy. (from a poem of the time)
Viewpoint 2: Faith and reason are separate avenues to the same Truth. This viewpoint, held by the majority of high-medieval philosophers, was that reason had a valuable role to play as a servant of revelation. By their very nature they cannot lead to contradictory conclusions, for Truth is one, and it can be reached through logic or faith. Note what happens to Galileo later in this history.
Viewpoint 3: By the fourteenth century a third viewpoint emerged in Christianity which held that reason and revelation lead to radically different, but equally true, conclusions. This was called the doctrine of "twofold truth". This eventually led to a dualistic view that held religion free from the constraints of logic and science uninhibited by faith (see 'Descartes', later in this history).
A second important philosophical issue during the High Middle
Ages concerned the relative merits of the Platonic and Aristotelian
traditions. Those following Plato placed a higher emphasis on
mathematics and deductive logic, seeking an understanding of the
true nature of reality, for which our phenomenal world is a less
real shadow. Those following Aristotle placed a greater emphasis
on inductive logic, looking for the nature of reality as it is
expressed in the phenomenal world.
The difference between deductive and inductive logic is described in 'More on Logic'.