# Intuition Behind the Definition of Prudence?

I'm having trouble seeing why an agent is said to exhibit "prudence" when u'''($\cdot$) > 0. How does having a utility function with a strictly positive third derivative make an agent act "prudently"? Thanks in advance.

For risk averse consumers with thrice differentiable utility $u^{\prime\prime\prime}>0$ is a necessary and sufficient condition for consumers to save more for tomorrow when they are really unsure what is going to happen in the future.