8 Best Philosophy Books That Will Open Your Mind.

 Letters From a Stoic by Lucius Annaeus Seneca.

Man’s Search for Meaning by Viktor Frankl.

Beyond Good & Evil by Friedrich Nietzsche.

The Daily Stoic by Ryan Holiday.

Ethics by Benedict de Spinoza.

Critique of Pure Reason by Immanuel Kant.

On the Genealogy of Morals by Friedrich Nietzsche.

Reasons and Persons by Derek Parfit.