Philosophy
The Philosophy of Language: Reference and Meaning
Quick fact
The philosopher Gottlob Frege pointed out that 'the Morning Star' and 'the Evening Star' both refer to the planet Venus, yet they have different meanings—you can think one without thinking the other, and statements like 'The Morning Star is the Evening Star' can be informative.
Why this is interesting
You use words like 'water' and 'love' every day without a second thought. But have you ever wondered: what makes a word refer to something, and what gives it its meaning?