… in 1975: Sc 663a se-tenant pair. Canadian Personalities. Design: William Southern.

Four stamps were issued this day in 1975 featuring “Canadian Personalities” and this pair seems to be the ones aimed at an English Canadian audience. (The other pair was Marguerite Bourgeoys and Alphonse Desjardins)
Here’s the Canada Post details on these two:
“Samuel Dwight Chown (Sc 662 / right)  was born in 1853 at Kingston. As a boy, he served in the army during the Fenian raids. At seventeen, he left home for Minnesota to make his fortune in hardware. An urgent telegram brought him back to Kingston where he discovered that nothing was wrong "except that his mother was lonesome for him". In 1874, having felt the call, Chown began preparations for the Methodist ministry. His ordination occurred in 1879. During the next twelve years, he served in small towns where he emphasized the virtues of temperance. At Kemptville, Ontario, he so antagonized the local liquor interests that they threatened to kill him. They burned the Methodist manse and church but only after Chown eventual transfer. Between 1892 and 1902, he lived in Montreal and Toronto a gained a reputation as an administrator. The Methodists appointed Chown as Secretary of their Department of Temperance, Prohibition and Moral Reform, in 1902. He rapidly expanded Department's work and it was soon dealing not only with alcohol but with women's rights, education, municipal sanitation, mental health, narcotics, prostitution and immoral stage productions among other things. Chown's "conviction that Christianity required a passionate commitment to social involvement" inspired his efforts. If the Churches did not act, he feared they would force "people to choose between an unsocial religion, which [could not] be Christianity, and irreligious system of social salvation".

John Cook (sc 643 /  left)  was born in 1805 at Sanquhar, Dumfriesshire, Scotland. He attended university at Glasgow and Edinburgh and became a Doctor of Divinity. He arrived in Canada in 1836 as Minister of St. Andrew's Presbyterian Church in Quebec City. A deep thinker and reasoner and a man of noble presence who would have been singled out among a thousand for his distinguished appearance, Cook was well suited to St. Andrew's, a church with a large and enlightened congregation in a city which was a hive of commerce and industry. Everyone was so happy with the new minister that he stayed for forty-seven years. His sermons were especially satisfactory. They were "models of literary form and texture ... [notable] for their beauty of diction, clearness of thought and lofty eloquence". Quebec City benefited from Cook's boosterism and his strong sense of progress. He loved Canada although he may have been slightly uncomfortable here. Until it was moved, a jail where public executions took place, was next door to his home. Doctor Cook had a great deal of business sense and was a "prince of committeemen". Inevitably he gravitated to some of the administrative boards and higher leadership positions in the Church. Certain British North-Americans elected him their Moderator in 1838 and again in 1844 when despite his best efforts, a Scottish schism divided the Canadian Church. He soon began to work for a reunion. All the diverse Presbyterian Churches in Canada finally united in 1875 and they recognized Cook's achievements by proclaiming him the first Moderator. Education was one of the Doctor's foremost concerns. He helped establish the High School in Quebec City and he ran the local Presbyterian College. Many regard him as "prime founder" of Queen's University which he served as principal, when no one else would take the job and as chancellor. Doctor Cook died in 1892 and will always be remembered for his "rare accomplishments and ripe culture..."