From both my experience and that of the people I've talked to, psychic ability seems to be hard-wired into the human condition. While I can't say for certain that everybody's psychic (after all, I haven't met everybody yet), most of the people I've encountered seem to have one or more signs of innate ability, whether functioning consciously or unconsciously.
At that point, the different systems of divination seem less to be methods that are graven in stone, and more like frameworks that enable us to get in touch with what is in our heads, and our hearts, and our spirits. Different systems of divination (palmistry, tarot, tea leaves, etc.) may each have their own strengths and weaknesses, but they all boil down to different ways of touching the Wisdom that is within us and without us.
When it comes specifically to palmistry, you'll find a lot of books with a lot of different systems for reading palms out there. Many say different things. Some actually say contradictory things.
So what do we make of that?
That it all works (if you do the following)....
If you want to learn from books, I recommend that you chose a book that speaks to you. Learn from that, and then add to it with information from other books and other sources that don't contradict the first one.
If you want to learn from this book (and I'm assuming you do, or you wouldn't be reading it), I recommend that you read it carefully, and try what I have to share with you. Take what resonates with you, and leave the rest, adding things from other sources that speak to you as you find them.
If you do this and listen to your own inner wisdom as to what is right when you do a reading, then you will find what you end up with will be amazingly effective...
No matter what book or system you choose...
I' m going to be teaching you the system that I've been working with for around 40 years. I look forwards to seeing how it evolves for you.