This article argues in favour of lowering the voting age to 16. First, it outlines a respect-based account of democracy where the right to vote is grounded in a respect for citizens’ autonomous capacities. It then outlines a normative account of autonomy, modelled on Rawls’s two moral powers, saying what criteria must be met for an individual to possess a (pro tanto) moral right to vote. Second, it engages with empirical psychology to show that by the age of 16 (if not earlier) individuals have developed all of the cognitive components of autonomy. Therefore, since 16- and 17-year-olds (and quite probably those a little younger) possess the natural features required for autonomy, then, to the extent that respect for autonomy requires granting political rights including the right to vote – and barring some special circumstances that apply only to them – 16- and 17-year-olds should be granted the right to vote.

Using literature, documents and parliamentary debates in Britain, Germany, The Netherlands, Austria, and Switzerland, nine arguments for and against lowering the voting age to sixteen are distinguished and critically assessed. The assessment is based on criteria such as logical consistency and empirical validity. It is argued that most arguments can hardly be defended with these criteria. However, this does not mean that the case for lowering the voting age is weak. This would only be the case if a voting age of eighteen is considered as valuable in its own right.