Good point here. Many confuse wisdom with “nyana” and this is one of the reasons for the arahantification of stream enterers that we see these days. Many get to believe a stream enterer is like an arahant or maybe even higher.
developing perfect ethics in thought
I don’t know why you would chose the worlds “ethics in thoughts”. Stream entry is described as been “acomplished in view” and as having made “the breakthrough of dhamma”. From my understanding of the suttas, a stream enterer is one witch has intelectually understood the non-existence of a self, witch requires a lot of contemplation on “higher teachings” found in SN chapter 2,3,4. From the understanding of non-existence of a self also comes the intelectual understanding of nibbana without imagining some form of consciousness in it. Another “stream entry test” we see in SN is that about “understanding the gratification, the danger and the escape in the case of the 7 factors of enlightenment”. My full opinion with a lot of sutta refference are here: How is stream entry achieved?
So in short I would describe it as the understanding of non-existence of a self due to contemplation on higher teachings. That is why first fetter removed is “self view” and the other 2 are things that follow from this understanding. I do not see why it should be described as “ethics in thoughts”
- the cause is ignorance (NOT desire, which is the Hindu teaching)
We see in the suttas that ingorance and craving are the 2 forces that drive future existence. But in the context of the 4 noble truths, I think attachment is the more appropiate one. We have a sutta for example where Buddha asks a villiger if he would suffer if his relatives or friends would get imprisoned or killed or impovrished and weather he would suffer if people who he does not know would have such things happening to them.
Everything is impermanent. Because of attachment to impermanent things, suffering appears when these things change. The proximate cause here seems to be attachment with ignorance been a non-proximate cause.