"人間は理性的な動物であると言われてきました。私はこれを裏付ける証拠を探し求めてきました。"

Simplified Meaning:

People often say that humans are logical creatures, capable of making decisions based on reason and facts. However, the speaker here has spent a long time trying to find proof of this idea but hasn't found much convincing evidence. This suggests that, in their experience, humans often act based more on emotions, impulses, or other irrational factors rather than pure logic. Think about situations where people knowingly make unhealthy choices, like smoking cigarettes even though they know it can cause serious health problems. This behavior illustrates the speaker's point: despite having the ability to make rational choices, people often don't. If someone wants to apply this idea to their life, they might try to be more mindful of their decisions, aiming to use logic and reason more frequently instead of acting on impulse or emotion. By doing so, they could make better choices that lead to improved outcomes in their life.