The Dictionary of the History of Ideas (originally published in 1973, but long out of print) is available in searchable and browsable form online. (A new print edition is also in production.)
A (very) few of the essays of special interest to early modernists:
Causation in the seventeenth century
Medieval and renaissance ideas of nation
Or to students of law and justice:
Or to academics everywhere:
(From the C18-L discussion list.)
One comment on “Dictionary of the History of Ideas”
That is so cool… Thanks for posting that.