Reason
This theme runs through several big questions. Here are the ones where it plays out.
The questions that illuminate it
Can we reach definitive certainties?
If nothing is ever certain, no knowledge holds firm and action loses its footing; yet to believe oneself certain is to risk shutting one's eyes and learning nothing more. To take a position is to say whether doubt is a form of honesty or a dead end.
Where does our knowledge come from: sensory experience or reason?
Does everything come from the senses, which nonetheless deceive us at times, or does the mind hold truths no experience could supply? Resting knowledge on experience alone deprives it of certainty; on reason alone, it cuts it off from the real world. To take a position is to say what to rely on, in the last resort, in order to know.
Are emotions an obstacle to thought or a source of knowledge?
Should we distrust what we feel, a disturbance that clouds judgement, hear in it a fine perception of what matters, or learn to train it? To take a position is to say how much credit to give our emotions when they contradict cold reason, and whether wisdom lies in silencing them, following them, or shaping them.
How do faith and reason relate to each other: agreement, conflict, or indifference?
Can one believe and reason without betraying either? Forcing them to agree risks distorting both, declaring them enemies forces one to pick a side, separating them protects each but leaves faith mute before knowledge. To take a position is to say what place a religious conviction can hold for someone who also wants to think freely.
What makes a belief justified?
From pseudo-sciences to rumours, countless beliefs present themselves as justified: what remains is to know what that warrant rests on, first certainties, the agreement of the whole, or methods that have proven themselves. Depending on the answer, we draw the line between knowledge and what merely looks like it in a different place.