Very though provoking book. As a teacher/researcher in information technology it opened my mind to inter/multi-disciplinary (and the complexity of it). The book will raise a lot of (good questions), and will take you out of your "box" :).
The book is in two parts of similar length:
I - "Science avec conscience" (Science with Conscience)
II - "Pour la pensée complexe" (For the Complex Thought)
The first one is the one that Edgar argues for the multidisciplinary need as a scientists/researchers (really convinced me, though I was already convinced provides very good points on the topic).
The second part is much more philosophical and analyses the complexity of (system-unity/order-disorder, resilience, cybernetics/system theory, many other relationships).. the universe, the self etc. based on many of his previous work.
I would recommend reading the first part at least.
The second one is much more "philosophical" aiming at (new) fundamentals for a complex though (as the title says).