Aristotle, First Principles Thinking, Limitations and Presuppositions

"The things best to know are first principles and causes, but these things are perhaps the most difficult for men to grasp, for they are farthest removed from the senses ..." - Aristotle

I am not sure did Aristotle said this or someone put words into his dead mouth. Anyway, we are told that Aristotle always look for "the first basis from which a thing is known" or first principles for every new thought he started. But it is the same Aristotle that said that a heavier object will fall at a faster speed. Why did he not apply his first principles thinking and do some experiment to prove it?

Like all human, Aristotle suffered from this - limitation.

First principle thinking is wonderful, except that it has to cope with two limitations:

1. Limited time and resources
   It is not possible do everything from first principles. There is not enough time, skills, knowledge, resources and power to do that. You have to choose. How are you going to make your choice? That brings us to the second limitation.
2. Presuppositions
   Everybody has presuppositions. There is not enough time, skills, knowledge, resources and power to remove all presuppositions.

Ultimately you need faith. For those things that you do not have time to apply first principles thinking, you have to accept by faith what your senses, gut feeling, friends, authorities or even Google tell you.

Without faith, you cannot even take one step forward. How do you know that the ground in front of you can take your weight when you did not conduct any experiment to prove that it can?