Excellent. This is the best Theological Survey of Calvin's thought that I have read to date and it is still the standard. If you want a fair and level headed survey of the origin and development of Calvin's theological thought, pick this one up. It won't disappoint for what it has proposed to do.
A brilliant, much neglected, book on Calvin's teaching. As a basic-but-serious introduction, I'm not sure it has been surpassed in the 70 years since it was first published in French. The outline of Calvin's life, the introductory material on the Institutes, and the summary of Calvin's theology, according to the plan of the Institutes, are all superb. It makes a good companion to the Institutes itself, since it engages with difficulties, puts arguments in context, and draws together helpful insights from Calvin's broader works. It is by no means just a simple summary of the Institutes - rather, it is a thoughtful engagement with Calvin's theology through that lens.
It has real limitations. He could draw a little more on the commentaries. More, Wendel reads Calvin through Neo-Orthodox eyes at times: this is very obvious in the doctrine of scripture in particular, where we are given ideas about the presence of error in scripture that are far more to do with Barth's successors than with Calvin. Another issue is his maximalist interpretation of Calvin's influences, assuming, for instance, influence of John Major and Nominalism for which there is no solid evidence, only possibility. Most of all, Wendel's critiques are somewhat bizarre, taking issue with Calvin's approach to paradox and seeing issues that are just... odd. Criticism is obviously legitimate in a work like this, but I suspect that this is the area that has dated most badly - three are criticisms that made sense in the mood twentieth century, and not now.
A less surprising issue is that, as a work originally written in French, the footnotes to other works are rarely useful unless you can follow them up in French, German, and occasionally, Latin.
In the end, though, Wendel isn't just helpful - he's remarkably prescient of some of the advances in Calvin scholarship of the last few decades. His critiques of those who insist on finding a theological 'center' that is a guiding logical principle to Calvin's 'system' is so important. His insistence on drawing from the breadth of Calvin's writing, fleshing ideas in the Institutes out with quotes from his polemical works, letters and commentaries gives us a genuinely rounded view. He shows us a picture of Calvin as a part of the broader 16th century reform, influenced by Bucer and Bullinger and Oecolampadius as well as Luther, making clear his place as a late arrival to the reform movement who was not seen as uniquely prominent at the time.
The (brilliant) work Steinmetz and Muller on Calvin gives much more depth to this picture, but if more people had listened to Wendel, would have been far less necessary as a corrective to Calvin scholarship of the twentieth century.
In short, a great place to start serious study of Calvin, giving a good picture of Calvin's careful, Biblical approach to theology, in advance of reading the key works by Steinmetz, Muller, and others.
In a similar way to Bainton's Here I Stand, with Luther, this attempts to use Calvin's own words to explain the man and his thinking, but it doesn't succeed nearly so well. Ultimately there is a lot of confusion and muddle, both in the writing style which confuses Wendel's words with Calvin's and in Wendel's inability to see the wood for the trees in his sumarising. Despite what many reviewers seem to say, this is not a book for beginners at all, using too many technical terms and assuming far too much theological grounding.
Another great barrier to its readability is the archaic English in translation. This goes both for Wendell's writing and the Calvin. It is very much akin to reading King James today - incredibly hard to read and meaning obscured by language. Nevertheless Calvin's own thinking is incisive and worthwhile. Despite Wendell's almost bizarre conclusion chapter when he goes on about contradictions which are nothing of the sort (rather natural theological tensions which Calvin is addressing); where he also says that Calvin has no system, clearly everything he has written show the opposite to be true.
As Wendel tells us, some have said that the centre of Calvinism is predestination. However from Wendel's discussion rather this is the end point. Calvin starts with the legalism - and legalism in the sense that there is rigidity rather than flexibility, haziness, elasticity - that God alone brings about salvation with no contribution from the sinner. From a biblical and Christian point of view this is true on the most basic level, however with humanity nothing is ever simple, black and white; rather there are always nuances and greys. Wisdom is the quality of recognizing this. However what Calvin does is starts with this uncompromising position and then have to build a bigger and ever more complicated edifice to sustain the position against common sense. The complications multiply and the arguments move further and further away from everyday reality until reaching the end point of predestination to either salvation or perdition. Christianity must also be practical and Calvin moves far from practicality and into dogma - religiosity.
While this is no part of Calvin himself - ultimately extreme Calvinsim leads to fatalism - why bother if your fate is already determined because you can do nothing about it. Truly this is not what God created humanity to be. For this reason I am no fan or Calvin nor his theology but this book did give me a much greater appreciation for the depth and breadth of his thinking, which accounts for his immense influence on Christianity to this day.
Wendel's exposition is clear, helpful, and judicious. There is no obvious partisan cast here, nor any especially ambitious interpretive agenda. Wendel does suggest late that the major theme is the absolute divinity of Christ, of which he adduces examples I find astonishing.
As I'm slated to spend this term actually reading the Institutes-- which I haven't before-- I can't comment on the persuasiveness of Wendel's case. His book appears to remain something of a classic, so I assume it's sound. Mostly, on this reading, it's served to whet my appetite for the real thing. That's a very decent accomplishment, all told.