Knowledge is like guns. It is a tool that in itself has no moral values. It is how it is used that makes it good or evil, or similarly (but not quite alternatively) lawful or unlawful.
The Preparatory Manual of Explosives 3rd Edition is a valuable reference book, full of great information rarely found elsewhere, however, it is also highly illegal to actually construct, or plan to construct anything in this book without the proper licenses.
It is particularly difficult to acquire those licenses, however, if you can legally create the compounds in this manual, then this is a great professional reference.
This is no “anarchist cookbook” of slapped together ideas with dubious credibility – this is a book for professionals and should be treated as such.
Once again, as I have said repeatedly, you should never make anything found in this book or other explosive cookbooks without the proper licenses, permits, and safety protocols in place. Not only can you kill yourself or innocent people, you can go to jail for a long time. Alternatively, if you are a terrorist and make bombs, you will deserve to get shot in the face by the police or armed citizen.