Answer: they are blindly driven by the will to pursue their selfish desires.
Step-by-step explanation:
Schopenhauer stated that human beings rarely guide their actions by rationality, but are rather instinctively motivated by the hope to seek their most selfish wishes. Reason only appears after the fact, once to rationalize something that was made out of impulsiveness.
Schopenhauer believed humanity to be cruel, because of their atrocious acts in pursuit of petty goals, making impossible to attain trust and security.