Truth is true. Rationality is rational. Science is scientific. Philosophy is philosophical. Virtue is virtuous. Beauty is beautiful. Pleasure is pleasurable. And so on.
To live your life guided toward rationality, filled with virtue, animated by beauty, and aimed at pleasure is almost unfailingly rational, virtuous, beautiful, and pleasurable. To reject reason, morality, greatness, and happiness, as goals and ideals, is almost invariably unreasonable, immoral, base, and miserable.
Life without truth, rationality, science, philosophy, virtue, beauty, and pleasure is evil incarnate. It destroys virtually all of your greatness and happiness.