A fairly typical English intellectual of that general period (i.e. my opinion of him is resoundingly negative), though not actually the one that did the most damage. As to his famous theory...
Malthus was fundamentally wrong about several things, but what turned him into the laughing stock of later centuries was one of the most important breakthroughs in the history of agriculture (i.e. the introduction of fodder crops) rather than a flaw in his reasoning. Essentially, his thesis was overtaken - and rendered absurd - by events. Previous population expansions in Europe had generally ended famine. And even today there are parts of the world that are clearly 'overpopulated'.