Niels Stensen (scientist/geologist) (Denmark 1969)

Stamp Niels Stensen (scientist/geologist) it reflects the thematic directions:

Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is called a naturalist or natural historian.

A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the study, diagnosis, prognosis and treatment of disease, injury, and other physical and mental impairments. Physicians may focus their practice on certain disease categories, types of patients, and methods of treatment—known as specialities—or they may assume responsibility for the provision of continuing and comprehensive medical care to individuals, families, and communities—known as general practice. Medical practice properly requires both a detailed knowledge of the academic disciplines, such as anatomy and physiology, underlying diseases, and their treatment, which is the science of medicine, and a decent competence in its applied practice, which is the art or craft of the profession.

A scientist is a person who researches to advance knowledge in an area of the natural sciences

Clergy are formal leaders within established religions. Their roles and functions vary in different religious traditions, but usually involve presiding over specific rituals and teaching their religion's doctrines and practices. Some of the terms used for individual clergy are clergyman, clergywoman, clergyperson, churchman, cleric, ecclesiastic, and vicegerent while clerk in holy orders has a long history but is rarely used