Many countries have constitutional provisions which prohibit discrimination based on certain characteristics (i.e. age, nationality, etc) while also - within the same constitution - having restrictions on voting right based on the very same characteristics.
For example, in the Estonian constitution, Section 12 states no one should be discriminated based on "nationality", "origin", or "other grounds". But later in Section 57, it restricts voting right to citizens of age 18 or older - this seems to constitute discrimination based on "nationality" and age (covered by the catch-all "other grounds").
Does this mean these constitutions are contradicting themselves? How do legal scholars reconcile these seemingly paradoxical provisions within their respective constitutions?