Enlightenment

German philosopher published his first work - 'Thoughts on the True Estimation of Living Forces' in 1747. Explaining the nature of space, Kant rejected a post of  Leibnizian racionalists, arguing that that metaphysic methods can prove the existence of essential force. In the end, Kant mainly focused on philosophical issues although he continued to write on science and similarly as Leibnizian also criticised Newton's views.

Kant had a burst of publishing activity in the years after he returned from working as a private tutor. In 1754 and 1755 he published three scientific works - such as- "Universal Natural History"and "Theory of the Heavens". Also he wrote "What is Enlightenment" and his famous quote about Enlightenment was "Enlightenment is man's release from his selfincurred tutelage. Tutelage is man's inability to make use of his understanding without direction from another. Self-incurred is this tutelage when its cause lies not in lack of reason but in lack of resolution and courage to use it without direction from another. Sapere aude! 'Have courage to use your own reason!'- that is the motto of enlightenment." This quote was a famous quote used to conclude the definition of Enlightenment. He proved that the people who lived during Enlightenment, knew at what era they lived and tried their best to contribute to sciences, maths and etc. These works were the major and important works of his carreer. 

Kant's philosophy is often described as the golden middle between rationalism and empiricism. He didn't accept either of both views but he gave credit to both. While rationalists argue that knowledge is a product of reason, empiricists claim that all knowledge comes from experience. Kant rejected yet adopted both, arguing that experience is purely subjective if not first processed by pure reason. Using reason while excluding experience would according to Kant produce theoretical illusion.

More of his famous quotes: 

1)"We are not rich by what we possess but by what we can do without."  

2) "Act in such a way that you treat humanity, whether in your own person or in the person of any other, never merely as a means to an end, but always at the same time as an end." - in one of his books called "Grounding for the Metaphysics of Morals."

'Thoughts on the True Estimation of Living Forces'  by Immanuel Kant- 1747