When looking at the New Testament, we get excited when we see a pattern emerging in Greek usage. It may not be a pattern that makes sense, but then we can rest assured that we are talking about a real human language here and not some robotic theoretical communication system for which there is simply no evidence among the languages of man. I am going to discuss the Greek word arché, in the next post or two, but let us first take a moment to see how important it is to understand the irrelevance of the why question. What we want to know is how does word A mean X and therefore what in fact does A mean? Sometimes to achieve this we go a step further with "when": When does word A mean X and when does word A mean Y? Why is not relevant. Why do we have the same word "could" in English for meaning A and for meaning B??
Meaning A: I could purchase the garage if I took out a loan.
Meaning B: I could purchase the garage because I took out a loan.
"Could A" is the conditional of the modal "can", and is not yet settled. I may choose to take out the loan, or I may not choose to do so. It is open.
"Could B" is the past tense of the modal "can", it is utterly settled, unchangeable and in the past. To combine the conditional and past, I am required to go down the wordy route of: I would have been able to purchase the garage if I had taken out a loan.
Imagine a thousand years from now if English were to change dramatically - and it most certainly will - and that this kind of usage had faded out. Researchers in this future age are desperately peering back into our time to try to understand quite how this strange word "COULD" actually worked. In different contexts, it seemed to function very differently. Sometimes it seemed totally settled. Sometimes it seemed very open. Then they might stumble on their "Ah ha!-moment" as the rule - our rule - began to emerge. It would be a much less useful exercise for these researchers to try to figure out quite why "COULD" functioned the way it did, for their primary motivation is to exegete the meaning of the sentences containing the defunct word.