The team at Global Policy: Next Generation were heartbroken to hear of the tragic and untimely passing of Dr. Nathan Alexander Sears earlier this year. GPNG is an initiative focused on amplifying the scholarship of early career researchers—exceptional thinkers at the beginning of their professional academic careers. As editors and as colleagues, we were not prepared to be writing in memoriam about one of our earliest contributors.

Dr. Sears contributed an exceptional article to the first edition of Global Policy: Next Generation (2020). It remains GPNG's most highly cited and engaged-with publication. In the video abstract of the article found here, Dr. Sears discusses the paper's argument and contribution to the field.

Among the many tragedies of Dr. Sears' passing is that his scholarly career was cut short just as it was beginning. He had defended his PhD dissertation at the University of Toronto in October 2022. The recency of this milestone achievement, however, belies a career already full of accomplishments, including work as a Government of Canada Cadieux-Léger policy fellow and several influential articles (Sears, 2017, 2020, 2021; Smith et al., 2020). Dr. Sears' work was at the cutting edge of research on global existential risk, using the tools of International Relations theory to understand why great powers choose to cooperate—or not—on human-induced civilisational threats from nuclear war to bioengineered pathogens to ‘unaligned’ artificial intelligence.

Dr. Sears' death is a profound loss for both the research and policy communities with which he so passionately engaged. His passing also leaves a hole in our academic community that is wider than just his research. Nathan was an engaging and passionate scholar who positively contributed to every community he was a part of. He was a thoughtful and respectful listener and a generous and enthusiastic peer. Despite the seriousness of his work and his intense concern with existential risk, Nathan was also known as someone with a great sense of humour—quick to laugh and armed with a bright and infectious smile.

This forum is a tribute to Dr. Sears' life through a reflection on his scholarship and research career. The five contributions consider the impact of Dr. Sears' published and unpublished research and the ideas he developed over the course of his too-brief career. The contributors pay their respects to Dr. Sears in the best way scholars know how—by engaging with, debating with, critiquing and expanding on his ideas. They also speculate about where Nathan's work may have gone in the future and the contributions to humanity he may have made. Those who knew Dr. Sears know that he relished intellectual debate: he would have truly enjoyed reading these reflections.

Our hearts go out to Nathan's family and all those in our community who are mourning him and the loss of such enormous potential. We hope this forum can amplify Dr. Sears' work so that his scholarship and intellectual contributions can live on.

今年早些时候，听到内森·亚历山大·西尔斯博士不幸去世的消息，“全球政策：下一代”团队感到心碎。GPNG是一项致力于扩大早期职业研究人员（处于职业学术生涯初期的杰出思想家）的学术成就的计划。作为编辑和同事，我们不准备写一篇纪念我们最早的贡献者之一的文章。

西尔斯博士为第一版《全球政策：下一代》（2020 年）撰写了一篇出色的文章。它仍然是GPNG引用率最高、参与度最高的出版物。在此处找到的文章的视频摘要中，西尔斯博士讨论了该论文的论点和对该领域的贡献。

西尔斯博士去世的众多悲剧之一是他的学术生涯刚开始就被终止了。他于 2022 年 10 月在多伦多大学进行了博士论文答辩。然而，这一里程碑式的成就是在最近才取得的，这掩盖了他的职业生涯已经取得的成就，包括担任加拿大政府 Cadieux-Léger 政策研究员的工作和几篇有影响力的文章（西尔斯，  2017 年，2020 年，2021 年；史密斯等人，  2020 年）。西尔斯博士的工作处于全球生存风险研究的前沿，利用国际关系理论的工具来理解为什么大国选择在人类引发的文明威胁上进行合作（或不合作），从核战争到生物工程病原体，再到“不结盟的人工智能。

西尔斯博士的去世对于他如此热情参与的研究和政策界来说是一个巨大的损失。他的去世也给我们的学术界留下了一个比他的研究更广泛的漏洞。内森是一位富有魅力且充满热情的学者，他为他所属的每个社区做出了积极贡献。他是一位深思熟虑、尊重他人的倾听者，也是一位慷慨而热情的同伴。尽管内森的工作很严肃，而且对生存风险非常关注，但他也被认为是一个很有幽默感的人——笑得很快，脸上挂着明亮而富有感染力的微笑。

本次论坛通过反思西尔斯博士的学术和研究生涯，向他的一生致敬。这五篇贡献考虑了西尔斯博士已发表和未发表的研究的影响以及他在短暂的职业生涯中提出的想法。撰稿人以学者们知道的最好方式向西尔斯博士表示敬意——通过参与、辩论、批评和扩展他的想法。他们还推测内森的工作将来可能走向何方以及他可能对人类做出的贡献。认识西尔斯博士的人都知道他喜欢学术辩论：他会真正喜欢阅读这些反思。

我们的心与内森的家人以及我们社区中所有哀悼他以及失去如此巨大潜力的人们同在。我们希望本次论坛能够扩大西尔斯博士的工作，使他的学术和智力贡献得以延续。