Recognizing that it was beyond the ability of man to come to know their creator by reasoning they constructed Gods based on observations with the intent of explaining things beyond their understanding.   

As with every thing that man creates so it was with their religions - they moved from the sublime to the ridiculous.   

The Greek philosophers rightly rejected the ridiculous pantheon of gods that had been constructed.   Socrates obviously received some sort of revelation from God since his departure from traditional religion was so abrubt and so pure.   His notion that the development of character was the greatest goal of life is in essence pre-Christian revelation.   In order for God to reveal Himself ( Jesus ) to mankind He became flesh and dwelt among us demonstrating the character of God and the pathway to Him.   

Unfortunately, the brilliant philosophical minds who followed Socrates used his principles as a basis for their systems.   However, they lacked his revelation.   As a result, they followed the same path as the religionists - from sublime to ridiculous.   

In what way were Plato, Aristotle and others ridiculous?   If you make a cake and leave out the sugar, it may look like a cake and may even smell like a cake, but it won't taste like a cake.   Those philosophers who followed Socrates lacked revelation.   Their exercises were simply mental gymnastics.   If you take hard looks at their work you find that they built their systems on air.   As such they are entertaining but not substantial.