You can get the book with bittorrent, btw
i dont think its illegal because the man is dead for 300 years already.
I read somewhere that economics is not a natural science, in the sense of providing objective answers to precise questions, but it is a political science. This can be very well understood by reading Adam Smith.
The main thrust of his book is on deregulation and freeing up of international trade. He explains in detail how special interests, like the domestic producers of textiles in England, got the governement to erect prohibit for import of textiles and export of wool....
He also explains with great clarity how this harms the country as a whole.
For trading, there are great parts having to do with pricing of commodities. I find them very helpful to keep my mind straight. But this is only useful to a trader of commodities with a time horizon of months or years, like myself, not the daytrader obviously.