Some things we know (or at least have evidence of) directly through sense experience.
E.g. (perhaps), "There are people in the room now."Some things we know (or at least have evidence of) through the records of our memory.
E.g. (perhaps), "My mother was in a wheelchair."We have evidence for other matters of fact through the relation of cause and effect.
Examples:
1. Sally believes Bill is at her door because she hears his characteristic knock.Bill being at the door causes Sally to hear that characteristic knock.
(The believed fact causes the evidential fact.)
evidential fact causal relation believed fact ---------- ---------- ---------- Sally hears the knock <-- causes --< Bill is at the door 2. I believe my bicycle in now on my carport.
I remember seeing the bicycle on my carport earlier this morning.
The bicycle is on the carport now because it was there earlier today (and no one has moved it).(The evidential fact causes the believed fact.)
evidential fact causal relation believed fact ---------- ---------- ---------- The bicycle was on the carport earlier this morning. >-- causes --> The bicycle is now on the carport. 3. I believe some people got seriously hurt because I see a crushed car on the ditch on the side of the road.
(The crushed car being in the ditch now and the people being seriously hurt are both collateral effects of a car crash.)
evidential fact causal relation believed fact ---------- ---------- ---------- The car is now in the ditch. <-- causes causes -->
\ /
The car crashed.People got hurt.