Forms of Knowledge
Broadly speaking, propositional knowledge is knowledge that a given proposition is true. For example, we might know whether it’s true that cat’s have nine lives, or if cats are allergic to poinsettias. Propositional knowledge doesn’t have to refer to facts about the natural world, of course. You might know that a triangle has three sides (conceptual knowledge) or that last summer you travelled to Spain (episodic knowledge/memory).
There are different types of propositional knowledge. We saw two examples above. Conceptual knowledge is knowledge we arrive at by reasoning and abstraction. If I write 4 + 6 = ? on the board, you know the answer is 10 without having to find four objects, then find six more objects and count them to see that the answer is ten. Knowledge that relies on direct, sensory experience like that is sometimes called empirical or a posteriori knowledge. If you don’t have access to the internet, and I ask, “is it sunny, cloudy, or rainy right now?” you can only have empirical knowledge of the answer - you have to go outside to see for yourself.
What about knowing how to something, like playing the cello or riding a bike? Knowledge how is procedural knowledge. This is sometimes lumped into a category like tacit or implicit knowledge. This is knowledge that we can’t (easily) express. Another example is emotional intelligence. Someone who naturally makes others feel welcome and included might have a hard time explaining how exactly they go about doing so.