Pure maths is.
Physics is applied mathematics.
Chemistry is applied physics.
Biology is applied chemistry
Sex is applied biology.
QED. 
Physics is applied math? I’m not seeing that one.
E=mc[sup]2[/sup], v=u+at and all that. But don’t think too deeply; it’s a joke.
OTOH, there’s also the well-known mathematical proof that women are evil. How sexy is that?
Almost there, but you haven’t proven that sex is sexy.
Not sure if you’re riffing off of this?
I should have known that XKCD would have already done it.
Sure, biology is just applied chemistry, and chemistry is just applied physics, and physics is just applied math. But math is just applied logic, and logic is just applied philosophy, and philosophy is just applied psychology, and psychology is just applied biology, and…
Logic reduces to Psychology.
Psychology reduces to Biology.
Biology reduces to Chemistry.
Chemistry reduces to Physics.
Physics reduces to Mathematics.
And Mathematics reduces to Logic.
There’s a hole in your logic,
Dear Enola, Enola,
There’s a hole in your logic,
Enola, a hole!
You think it’s a loop, but biology is just applied turtles.
God is love.
Love is blind.
Stevie Wonder is blind.
Therefore…
Tis women makes us love
Tis love that makes us sad
Tis sadness makes us drink
And drinking makes us mad.
- 17th-century catch
Nothing is better than true love. And a crust of bread is better than nothing. Therefore, a crust of bread is better than true love.
“It is not true that an MIT student would rather think about calculus than have sex. It is true, however, that he will think about calculus while having sex, and hence enjoy it more.”
Psychologists think they’re biologists.
Biologists think they’re chemists.
Chemists think they’re physicists.
Physicists think they’re God.
God thinks he’s a mathematician.