The study of any subject must start with something.
The study of economics is the investigation of human action. Why do we act? Because God command us to do so in Genesis 1:28:
28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
This presents an exceptionally large epistemological problem. I have already started with something in my apologetic. I have started with God.
Consequently, let us take a step back. Move further backward in the ratiocination.
What do we know about humanity and how do we know it? How we answer that question will determine a great deal of the outcome. Is man the product of naturalistic processes? A divine plan? Or some gooble-dee-gook mixture of the two?
If humanity is the product of naturalistic forces (matter, time and chance) then there is no point in studying any subject. Such a study can only result in an understanding that is based on the uncertainty of matter, the finite nature of time and luck. The starting point is not fixed. There is no immutability. What exists today, may not be tomorrow.
The study will have no lasting quality because it is the product of uncertainty. Consequently, human thoughts are subject to unreasoned forces (which are based on matter, time and chance) that push or pull the conclusions in various directions. Sometimes, from our perspective, which is based on matter, time and chance, the conclusion will align when our arbitrary sense of “logic”. Other times, they will not.
The principle of uncertainty will permeate all aspects of the study. Hypothesis building, observations and conclusions will all be uncertain because the universe itself is uncertain, especially mankind. There is no certainty. Each new day, there may be an entire set of new rules.