While Malebranche does give a virtually complete account of his system in the Search, it's in bits and pieces throughout the (lengthy) work. If you're looking to learn what Malebranche's system was, I recommend instead getting his Dialogues on Metaphysics and on Religion, which are a much more concise and direct explanation of his system. Indeed, I'd recommend reading that book before this one regardless of your ultimate aim, since as this is a translation of the last edition of the Search, you'll find Malebranche himself often points the reader to his dialogues rather than go over everything again, and I'm not one to argue with the author!

So now you're probably wondering what this book actually is. Well, it's a treatise on method, much like Descartes' Discourse on Method, and shares much the same view as that book; hardly surprising given that Malebranche was a Cartesian. In other words it's an argument for the Rationalist method of enquiry, that is, starting with self-evident truths and deducing new truths from those. Malebranche also gives other pithy advice, such as not taking every word ancient others say to be true just because it's highly respected on so on. In addition he also goes into some detail about how Original Sin supposedly messed everything up and made us slaves to our senses.

And that's pretty much it. I recommend you read it at some point, particularly if you have a Rationalist bent yourself, but make no mistake, there are many other works that are better and more important to read before this one. What ultimately lets it down is that it's simply too long for the amount of material contained within.

Malebranche's importance as a philosopher has been rediscovered in the past 50 years. I say "rediscovered" because Malebranche was extremely influential in his time--garnering disciples both on the continent and in Great Britain. Locke, Liebniz, Berkeley, Hume, Reid, et al. owe much to his work. In the Search we find Malebranche's main arguments for the doctrine of vision in God and occasionalism. This latter theory held a prominent place in the 17th century as a solution to Descartes' famous mind-body problem. Of Malebranche's work, the Search is the most important, containing a nearly complete account of his philosophical and theological system. One note of caution, the Malebranche of the Search after Truth did have a tendancy to ramble (not unlike Locke). In reading it, one will have to wade through tedious sections on the psychology of those who take themselves to be witches or werewolves and the optical illusion of the moon's image on the horizon. However, Malebranche's opus is worth reading, especially for anyone interested in the development of philosophy during its most elegant time.