Question: Viktor von Weizsäcker was uncle to what German physicist and philosopher?
Context: Martti Olavi Siirala (November 24, 1922 – August 18, 2008) was a Finnish psychiatrist, psychoanalyst and philosopher.  He was inspired by psychoanalysis, the anthropological medicine of Viktor von Weizsäcker and the existential philosophy of Martin Heidegger.  The outcome was a unique synthesis theory that Siirala called social pathology. Carl Friedrich Freiherr von Weizsäcker (28 June 1912 – 28 April 2007) was a German physicist and philosopher.  He was the longest-living member of the team which performed nuclear research in Germany during the Second World War, under Werner Heisenberg's leadership.  There is ongoing debate as to whether or not he and the other members of the team actively and willingly pursued the development of a nuclear bomb for Germany during this time. In nuclear physics, the semi-empirical mass formula (SEMF) (sometimes also called Weizsäcker's formula, or the Bethe–Weizsäcker formula, or the Bethe–Weizsäcker mass formula to distinguish it from the Bethe–Weizsäcker process) is used to approximate the mass and various other properties of an atomic nucleus from its number of protons and neutrons.  As the name suggests, it is based partly on theory and partly on empirical measurements.  The theory is based on the liquid drop model proposed by George Gamow, which can account for most of the terms in the formula and gives rough estimates for the values of the coefficients.  It was first formulated in 1935 by German physicist Carl Friedrich von Weizsäcker, and although refinements have been made to the coefficients over the years, the structure of the formula remains the same today. Robert Klaus Freiherr von Weizsäcker (born 6 December 1954) is a German Economist and Honorary President of the German Chess Federation.  Since 2003 he has held the Chair of Economics, Public Finance and Industrial Organization at Munich University of Technology.  He is the eldest son of the late former German President Richard von Weizsäcker (1920-2015). Viktor Freiherr von Weizsäcker (21 April 1886 in Stuttgart – 9 January 1957 in Heidelberg) was a German physician and physiologist.  He was the brother of Ernst von Weizsäcker, and uncle to Richard von Weizsäcker and Carl Friedrich von Weizsäcker.  (For his family tree, see Weizsäcker.) Concentrative movement therapy (CMT) is a psychotherapeutic method for group and individual therapy which is based on thought models stemming from psychodynamic psychotherapy and depth psychology.  Taking as its point of departure the theory that perception is composed of sensation and experience (Viktor von Weizsäcker), CMT is interested in the conscious perception of the body in the "here and now" against the background of the individual life and learning story. Viktor von Struwe (1892-1964) was a German film producer.  He also worked as an assistant director on four films.  He is sometimes credited as Viktor von Struve. Ernst Heinrich Freiherr von Weizsäcker (25 May 1882 – 4 August 1951) was a German naval officer, diplomat and politician.  He served as State Secretary at the Foreign Office of Nazi Germany from 1938 to 1943, and as its Ambassador to the Holy See from 1943 to 1945.  He was a member of the prominent Weizsäcker family, and the father of German President Richard von Weizsäcker and physicist and philosopher Carl Friedrich von Weizsäcker. Marianne Viktoria Armgard Helene Doria Freifrau von Weizsäcker, née "von Kretschmann" (born 17 May 1932 in Essen) is the widow of Richard von Weizsäcker, the President of West Germany and reunited Germany from 1984 to 1994. Elisabeth Raiser (born as Bertha Elisabeth Freiin von Weizsäcker in Zürich on 18 August 1940) is the daughter of Carl Friedrich von Weizsäcker and a former President of the German Evangelical Church Assembly.  Her husband is Reverend Dr. Konrad Raiser.
Answer: Carl Friedrich von Weizsäcker