Edmund Gustav Albrecht Husserl (Dr. phil. hab., University of Halle-Wittenberg, 1887; Ph.D., Mathematics, University of Vienna, 1883) was a philosopher who is deemed the founder of phenomenology. He broke with the positivist orientation of the science and philosophy of his day, believing that experience is the source of all knowledge, while at the same time he elaborated critiques of psychologism and historicism.
Born into a Moravian Jewish family, he was baptized as a Lutheran in 1887. Husserl studied mathematics under Karl Weierstrass, completing a Ph.D. under Leo Königsberger, and studied philosophy under Franz Brentano and Carl Stumpf. Husserl taught philosophy, as a Privatdozent at Halle from 1887, then as professor, first at Göttingen from 1901, then at Freiburg im Breisgau from 1916 until his 1928 retirement.
The book consists of lectures by master Husserl; it is clearer than Logical Investigations, but not an introductory work as you could find in other philosophers' lectures like Adorno or Hegel. Husserl goes for the kill, especially against psychologism. He makes a sharp remark against evolutionary nonsense (with a Nietzschean touch) and demonstrates an incredibly clear knowledge of English philosophers.
Here he talks about noetics, not yet about noematics. Noetics is the theory of the norms of knowledge. Husserl goes for the essential, which remains the same and independent of subject and object, free from the empirical.
Husserl discusses radical ontology, a project that Heidegger would later undertake. Yet Husserl already gives a glimpse of what is coming: a more profound understanding of reality, independent of the empirical—reality is not empirical. (Interestingly, this insight could help in understanding the quantum problem of reality.)
There is also a good, although lengthy, example of the phenomenology of time focused on sound.
There is an early stage of a theory of science that later would appear in Popper's research: the probabilistic aspect of all scientific research and falsifiability (every scientific discovery is not final, always open to being refuted).
I'm not going to recommend it, but if you want to learn, let's go.
It feels like a small gift from the gods that the page headings to Ch. 4 of this edition are consistently printed as "noetics AS theory of justification" on verso pages, and "noetics OF theory of justification" on recto pages.