I think my earliest memory of Star Trek is of a rerun of “Arena” — the original series episode pitting William Shatner’s Capt. James T. Kirk against a hissing, reptilian alien captain of a race called the Gorn.

“Arena” was about more than going toe-to-toe with a menacing adversary in a dragon mask. It was ultimately about the power of technology — not just the now-quaintly futuristic technology of creator Gene Roddenberry’s 23rd century, but about the technological leaps that got us there. Specifically, it was about the discovery of gunpowder.

“Arena” was also about a moral leap — the leap from self-interest and concern for one’s kin and clan to universal empathy and compassion. “By sparing your helpless enemy who surely would have destroyed you,” Kirk is told by a super-powerful alien sitting in judgment, “you demonstrated the advanced trait of mercy — something we hardly expected. We feel there may be hope for your kind.”

Among the central characters, it was Leonard Nimoy’s Mr. Spock who most embodied the show’s “Trekkiness.” Kirk was a two-fisted, lady-killing hero who in many respects could have been at home in a Western. Spock was a less familiar sort of hero: aloofly cerebral, dignified, scientifically minded, seemingly emotionless. Kirk was the kind of alpha male who might well shoot for the stars, but Spock represented a class of technocrat who would make such voyages feasible.

Star Trek as a whole promoted techno-optimism and wound up instilling countless fans with a love of science, space and technology, not to mention inspiring a number of real-world inventions — but Spock in particular helped make being a scientist, along with being smart and calmly rational, cool for countless Americans.

It is hard to overstate the cultural impact of Star Trek. I don’t mean to gloss over the limitations of the original series and of most subsequent expansions of the Star Trek universe. Philip J. Fry of Futurama’s succinct summary of the show — “79 episodes, about 30 good ones” — is pretty much on the money. Still, Star Trek changed everything, or at least it contributed in a mighty and enduring way.

In the portrait of the utopian Federation, Star Trek showed us Roddenberry’s vision of what mankind should aspire to be. A picture is worth a thousand words, and one key aspect of Roddenberry’s vision of the future was right there on the bridge of the Enterprise, with all-American Kirk flanked by a black female communications officer, an Asian helmsman and, later, a young Russian ensign. In the midst of the Cold War, the civil-rights movement and second-wave feminism, these were powerful statements.

Most exotic of all was the science officer, Spock, whom a recent NPR story calls “otherness personified.” Complicating the picture, Spock wasn’t simply alien; he was half Vulcan, half human, opening the door to a variety of themes: reason vs. emotion; nature vs. nurture; racial and cultural mixed heritages. Precisely by denying his emotions, Spock affirmed their importance, at least for us.

Roddenberry’s overarching vision was broadly humanist, a term often used synonymously with “secular humanist.” Roddenberry was a secular humanist with a dim view of religion, but Trek’s humanism, while largely secular, was often compatible with the historic Christian humanism of St. Thomas More and Erasmus.

Star Trek affirmed the equality and dignity of all people, extending this to nonhuman peoples of every hue and description the makeup department could supply. Fear of the unknown or alien was rejected in favor of curiosity and openness to all.

The show was also humanistic in its affinity for the humanities. Shakespeare cropped up frequently on the original series, perhaps most strikingly in a staging of Macbeth on the Enterprise in the original series episode “The Conscience of the King.” Other sources of literary references include classical antiquity and the Bible.

Despite Roddenberry’s secularism, Star Trek’s record on religion is not simply negative, but mixed. Even in the original series there were positive religious elements, and after Roddenberry died, show runners took the ongoing franchise toward what I would argue is a more humanistic view of religion as a fundamental part of human experience.

An episode co-written by Roddenberry depicts a near-parallel Earth with a version of ancient Rome that enslaves peaceful dissidents who apparently call themselves “children of the Sun.” In the end, Uhura realizes that they had misunderstood: “Don’t you understand? It’s not the sun up in the sky. It’s the Son of God.” In this parallel Roman Empire, apparently, a parallel Christianity has arisen, enduring persecution there, as it did here.

As the franchise developed, Spock was a key element in the Trekverse’s growing openness to spirituality and religion. Spock’s “otherness” included a certain mysticism, perhaps linked to an Asian vibe present even in the original series and much more in later versions.

The feature films upped the ante considerably on Vulcan spirituality. In the Nimoy-directed Star Trek III: The Search for Spock, we learn that before dying in the previous film, Spock imparted his katra — his spirit or soul — to McCoy, so that his spirit could be brought to Vulcan and find rest.

The spinoff series went a long way toward complicating Roddenberry’s naive future, taking the vagaries of human nature, politics and conflict in a more realistic direction. An increasingly frank acceptance of religion, especially Bajoran and Klingon religion, became an important theme. In time, it was even possible for a character to mention attending Mass at St. Peter’s in Rome!

The ongoing cultural influence of the Star Trek phenomenon is incalculable, and Leonard Nimoy’s contributions are an immense part of that. Nimoy wasn’t just an actor doing a job; in a real sense, he was a co-creator who helped to define his character in many ways.

His Jewish heritage gave him an experience of “otherness” to draw on, even before the pointed ears and arched eyebrows went on. Among other things, Nimoy famously adapted the Vulcan salute from a liturgical gesture used during the Jewish priestly blessing he spied in synagogue growing up.

It’s remarkable how real and important Nimoy made this fictional character for so many of us. “I have been, and ever shall be, your friend,” Spock said to Kirk in that unforgettable death scene at the climax of The Wrath of Khan. Many feel that we have indeed lost a friend. McCoy’s line, “He’s not really dead as long as we remember him,” rings hollow. I prefer to hope, and pray, to see him as no one ever has — not Spock, but Nimoy — in the great sequel to which this world is only a poor pilot episode.

Steven D. Greydanus is the Register’s film critic. He is the creator of Decent Films.