Philosophical Foundations of Neuroscience, An Introductory Course in Computational Neuroscience, and Principles of Neural Design - all bought used for an okay p

Philosophical Foundations of Neuroscience, An Introductory Course in Computational Neuroscience, and Principles of Neural Design - all bought used for an okay price. Not exactly very theoretical books, but the topic fascinated me recently and I have to get started somewhere. Recommendations always welcome. Edit: I even have another half a dozen of them in my cart, but I can't keep buying books...