Columbus: 1620

And therefore it is fit that I publish and set forth those conjectures of mine which make hope in this matter reasonable ; just as Columbus did, before that wonderful voyage of his across the Atlantic, when he gave the reasons for his conviction that new lands and continents might be discovered besides those which were known before; which reasons, though rejected at first, were afterwards made good by experience, and were the causes and beginnings of great events.

--From The New Organum--

Writing down your theories, conducting an experiment based on those theories, and then learning from your experiences. Sounds like a scientist to me.