Week 9 class 1 and 2
Knowledge and Reliability
-knowledge is “internally certifiable” if (1) there is an argument which shows that P must be true and (2)
the premises of that argument are knowable a priori or by direct introspection
-Descartes demanded that all knowledge be internally certifiable
-In most cases of knowledge there is an argument with (1) a subjective premise (2) an objective conclusion
and (3) a ‘linking premise’
-ex. I know that grass is green
-why: because grass looks green (subjective premise) and if grass looks green it is green (lining premise)
-problem: I have to know the linking premise
ohow can I know this?
oDanger of a regress ( I know the linking premise only because I know something else…)
-maybe I don’t need to know the linking premise
-maybe the linking premise merely needs to be true
-this is the idea behind the reliability theory of knowledge
What is epistemic reliability?
-analogy: a reliable thermometer
-the thermometer produces representations of temperature, that can be accurate or inaccurate
-a reliable thermometer is one which produces accurate readings in the conditions for which it is designed
oconsider the difference in reliability in an oven thermometer when used in an oven if used to take a
oan oven thermometer is not meant to read humans
Is there a skeptical style argument against reliability?
-is the thermometer unreliable because there are situations in which it does not work properly?
oAll instruments are unreliable in some situations
oSo therefore no instrument would ever be reliable
oThat doesn’t seem right
-is a thermometer unreliable if we don’t know whether it is in a situation in which it is reliable?
oSay we don’t know if thermometer X is broken or not
oDoes out lack of knowledge make X unreliable
oIt seems not – whether X is reliable or not depends just on X and its situation; it does not depend
The analogy between reliability and knowledge
-a person is like thermometer, except where the thermometer measures temperature, the person ‘measures’
-S knows P if
1. S believes P
2. P is true
3. S is reliable about P (ie. Under the circumstances, if S believes P then P must be true)
-note the “must” in clause (3)
othis is the concept of necessity
owhy is it needed here???