The Eighteenth century was a period with a distinctive character of its own within the history of civilization and medical knowledge, and is sometimes extremely difficult to pigeonhole neatly. The century is generally presented to us as one of frivolity: all fops and powdered ladies. This is certainly true. But the Eighteenth century was first and foremost the century of enlightenment, of reason and sometimes of a determined break with anything connected with the darkness of the past.

The Eighteenth century brought amazing discoveries in all fields of human knowledge. In the beginning at least, philosophy was still a great influence in the field of scientific thought in general and medicine in particular due to the typically enlightenment view that all problems may be resolved through the application of pure reason. As the century progressed, the discipline of medicine began to be dominated less by philosophy and more by scientists working within physical and natural disciplines. In the Seventeenth century, doctors were divided between Iatrochemists (who believed that the body is a kind of chemical laboratory, a factory where various functions are performed spiritually through virtues residing within individual organs) and Iatrophysicists (a much more experimentalist and Galilean movement, which saw the human body as a true machine within which functions took place in accordance with mathematically measurable mechanical laws). In the Eighteenth century, the discipline of medicine was dominated by two diametrically opposite concepts: vitalism (which claimed that a vital force lay at the basis of life) and mechanism (which claimed that vital phenomena are characterized by matter and movement and thus subject to physical laws).

The main medical movements which began to become apparent during the first half of the Eighteenth century subsequently formed the basis for true schools of thought. These may be summarized as follows:

1. ANIMISTIC MOVEMENT, G. E. Stahl;
2. BIOLOGICAL MECHANISTIC MOVEMENT; F. Hoffmann;
3. VITALISTIC MOVEMENT, J. Brown.

Two great medical systems arose from a new trend toward the systematic (i.e. the construction of systems of thoughts, of doctrines) and the influence of romanticism on eighteenth century medicine

1. MESMERISM, F. Mesmer;
2. HOMEOPATHY, C. F. S. Hahnemann.

While the Sixteenth century placed science on a new footing and the Seventeenth century opened up new horizons of study through the introduction of microscopic anatomy, it was not until the Eighteenth century that Anatomy finally began to become an accepted part of clinical medicine. Normal Human Anatomy had some eminent proponents during this century, particularly in Italy. The most distinguished scientist of his century, G.B. Morgagni, was a native of Forlì. This renowned anatomist and founding father of the discipline of pathological anatomy (the study of disease-induced changes in organs) described, amongst other things, the urethral glands.

He also improved medical understanding of the insertions of the sternothyroid and hyothyroid muscles and was responsible for describing the highest nasal concha (known as Morgagnis concha) and the nodules of the pulmonary artery sigmoid valves.
G. B. Bianchi (1681-1761), a contemporary of Morgagnis, was called in 1720 to teach Anatomy at the University of Turin. He was particularly interested in the tear ducts and genital organs. Another famous contemporary of Morgagni and Bianchi was the Venetian Giandomenico Santorini (1681-1737) who was author, in 1724, of Observationes anatomicae. His particular area of interest was the central nervous system. He showed that the brain was not a gland as was commonly thought at that time. He also studied the muscles of the tongue and epiglottis. Another distinguished anatomist, one of the greatest of his century, was the German B. Sigfrido Weiss (1683-1771) who was better known by the Latinized version of his name, Albinus. He wrote De ossibus corporis humani (1726) and a work devoted to myology (study of muscles) entitled Historia musculorum hominis in 1754. Weiss was also known for his notes to the anatomical tables of Bartolomeo Eustachio. Another celebrated anatomist, L. Heister (1685-1758), devoted himself to the specific field of splanchnology (study of the viscera or internal organs of the human body).

Heister was able to provide an exact description of blood vessels by injecting them with mercury. His name is linked to the spiral valve of the cystic duct (Heisters valve). These advances within anatomy brought great advances in the discipline of physiology (study of the functions of the human body) due to the efforts of A. von Haller (1708-1777), a native of Bern. Von Haller was not only the father of physiology but also a student of embryology (study of the evolutionary stages of bodies from conception to birth) and teratology (study of monsters, particularly fetal). The Italian biologist and naturalist L. Spallanzani (1729-1799) also deservedly occupies a prominent position in the history of physiology.

Spallanzani added his authoritative voice to the long debate over the argument of spontaneous generation (at one time it was believed that simpler living organisms could arise spontaneously and were not derived from other organisms, although this theory is no longer accepted). He took the side of the advocates of pre-existence who claimed that all living beings (even the simplest) are derived from other living beings. Spallanzini showed that infusorians (single-celled organisms which appear if an organic substance is left to decompose in the water) originate solely from pre-existing germs. If the germs are destroyed (by heat, for example), the infusions remain sterile. Spallanzani studied animal generation with great enthusiasm and carried out numerous experiments on fertilization in frogs, toads and dogs. He showed that fertilization cannot take place without direct contact between the egg and the semen, thus refuting the widespread belief that spermatozoa fertilize an egg by means of a vapor known as the aura seminalis. He also examined various physiological matters relating to the circulation of blood: he made the observation, for example, that blood flows from the arteries to the veins through the capillaries in chicken embryos.

Leopoldo M.A. Caldani from Bologna (1725-1813), the anatomist and physiologist who succeeded Morgagnis in Padua, was concerned with the embryology of the nervous system. Caldani investigated the adult nervous system, the chyliferous vessels, the organ of hearing and the circulatory system. In the field of physiology, he openly ascribed to Hallers theories on irritability. He wrote two works: the Istituzioni di Anatomy [Fundamental principles of Anatomy] (1787) and the Istituzioni di Fisiologia [Fundamental principles of Physiology] (1787).
Felice Fontana (1730-1805), the great biologist and naturalist from Trentino who became director of the Museo della Specola (Observatory Museum) in Florence in 1771, was a near contemporary. Fontana was responsible for identifying the structure of nerve and muscle cell nuclei. He devoted himself mainly to a study of microscopic nerve structure.

In 1775, another great Italian scientist was appointed professor of anatomy in Acqui: V. Malacarne of Saluzzo (1744-1816). Malacarne was mainly concerned with aesthesiology (study of the sense organs) and neurology (study of the nervous system). He investigated the central and the peripheral nervous systems. The anatomist and surgeon G. B. Palletta (1747-1830) was a contemporary of Malacarne. He mainly studied the structure of the uterus and the tunica vaginalis testis (one of the six layers forming the coating of the testis) in addition to the buccinator or buccal nerve (which supplies the sensitive nerve endings in the cheek).
Paolo Mascagni, another eminent Italian scientist (1752-1815) taught anatomy, physiology and chemistry at the S. Maria Nuova Hospital in Florence (part of the University of Pisa). Mascagni carried out his most important scientific work on the lymphaticvessels. In 1819, he published an Anatomy for use by students of painting and sculpture. A general introduction to anatomy was published in 1819. The year 1823 saw the publication of Anatomia Universa, which Mascagni completed in 1815, the year of his death. This work contains extremely fine illustration plates showing, among other things, the lymphatic vessels, which the Italian scientist investigated in depth.

Another contemporary of Mascagni was the great surgeon and distinguished anatomist Antonio Scarpa (1752-1832), one of Morgagni's disciples. He studied the vestibular ganglion (which bears his name) and the nasopalatine nerve. He carried out extremely interesting and detailed studies into the organs of hearing, smell and sight. The anatomist gave his name to Scarpa's triangle, located on the front of the thigh.

The French surgeon and physiologist M.F. Xavier Bichat (1771-1802), who also lived between the Eighteenth and Nineteenth centuries, taught anatomy, physiology, surgical anatomy and pathological anatomy. The story goes that in the Parisian hospital Hotel Dieu, he managed to carry out more than six hundred autopsies in a single winter (an autopsy is carried out with the aim of finding changes in a cadaver and interpreting them in the light of symptoms observed during the life of the patient). A staunch upholder of the vitalist doctrine, Bichat believed that life is made up of the collection of vital properties which keep us from death. He outlined these theories brilliantly in a work written in 1799: le Recherches physiologiques sur la vie et la mort. The French scientist is unanimously considered the founder of histology (the morphological study of tissues, i.e. the constituent materials of the organs). Bichat was responsible for human anatomy becoming less a purely descriptive discipline and more a study of the intimate structure of organs and tissues, both normal and diseased. Bichat identified 21 types of simple tissues, which he described in his most important work: a general Anatomy dating from 1801.